Method of forming metallic closures



Sept. 29, 1942. L A 2,297,643

METHOD OF FORMING METALLIC CLOSURES Filed April 5, 1940 n lil u' K5 Patented Sept. 29, 1942 METHOD OF FORMING METALLIC CLOSURES John J. Williams, Wheeling, W. Va., assignor to Hazel-Atlas Glass Company, Wheeling, W. Va., a corporation of West Virginia Application April 5, 1940, Serial No. 328,119

2 Claims.

The invention relates to a method of forming metallic closures of the lug type, and particularly to the forming of lug closures in which the lugs will have a doubled over edge, for engagement with the container.

One of the objects of the invention is to provide a method by which caps having lugs with a doubled over edge can be manufactured with ease and at a high rate of production.

Another object of the invention is to provide a method which greatly reduces the amount of metal required in the manufacture of caps of this type.

Various other objects and advantages of the invention will be apparent to those skilled in the art, from the following detailed description, when taken in connection with the accompanying drawing, in which,

Figure 1 is a vertical sectional view of the cap blank.

Figure 2 is a similar view of the blank after the first operation has been performed thereon.

Figure 3 is a similar View of the blank after the second operation has been performed thereon.

Figure 4 is a vertical sectional view of the completed cap.

Figure 5 is a bottom plan view of the completed cap, and

Figure 6 is a perspective view of the completed cap.

Referring to the drawing in more detail, numeral l refers to the cap blank, which is formed from sheet metal by any ordinary out and draw die. The blank consists of a top 2 and a skirt, 3.

A portion of the blank skirt is bent inwardly,

throughout the periphery of the skirt, preferably to a position substantially parallel with the top of the blank. This inturned flange t is shown in Figure 2, and its inner edge is referred to by numeral 5.

The next step of the process is to double the inner raw edge 5 back upon the flange t, thus forming a reenforced, double-thickness, rounded edge 6. The doubled under portion is referred to by numeral 1. be performed by any desired apparatus, but preferably it is performed by a spinning operation. In Figure 3 the edge is shown as doubled under, and that is the preferred form, but of course it could be doubled over if desired. As will appear K hereinafter, portions of the double-thickness edge 6 become the edges of the cap lugs which engage the container, and hence there is no sharp raw edge lug contacting the container. And this highly desirable result is accomplished by the This step of the process may 4 use of an extremely small amount of metal, which is of great importance.

The next and final step of the process consists in bending the flange 4 downwardly and against the skirt 3, except where the lugs are to be formed, and in bending the lug forming portions downwardly to the desired extent, for example to the angular position shown in Figure 4. This operation is performed by a die, and may be accomplished by applying pressure directly to the flange except at the points where the lugs are to be formed, whereby the lug forming portion will be drawn down to the desired angular position by reason of the remainder of the flange being forced all the way down against the skirt; or, the operation may be performed by placing fingers under the flange at the points where the lugs are to be formed, and then applying pressure to the entire flange, whereby the fingers will positively determine the angular position of the lugs, while the remainder of the flange will be forced downwardly and outwardly against the skirt, as before. The completed cap is shown in Figure 4, 5 and 6, wherein the lugs are referred to by numeral 8. Three of these lugs are shown in the present cap, but of course any desired number of lugs may be provided. A liner, not shown, is usually mounted in the top of the cap.

From the foregoing description it will be apparent that I have provided a very simple and eflicient method for producing this cap at a high rate of production, and by the use of a minimum amount of metal.

Other methods of manufacturing this general type of cap, with double-thickness lugs, have been proposed heretofore. But all such prior methods involved the formation of an incurled bead, from which bead the double-thickness lugs are formed. Caps made by prior methods, however, require a relatively large amount of metal, and the lugs are of double-thickness throughout their entire extent, while for practical purposes the same desirable results are produced by simply providing the lugs with a double-thickness or reenforced edge. By the present method the double-thickness lugs may be formed by doubling back a minute portion of the flange to eliminate the raw edge, or the flange may be doubled back to any extent desired.

In the cap disclosed herein the curvature of the inturned lower edge of the skirt is uniform throughout the periphery of the cap, and neither the lugs nor the positions of the lugs are visible from the exterior, but the method is not limited to the manufacture of caps having these features.

Having fully described the invention, what I claim is:

1. The method of manufacturing metallic caps which comprises forming a blank having a top and a cylindrical skirt with a raw edge, bending a portion of the skirt adjacent the raw edge inwardly throughout its periphery to form an inwardly extending substantially planar flange, engaging the raw edge of the flange and by a spinning action doubling .the free edge of the flange upon itself and substantially in contact with the body of the flange, and thereafter forming spaced portions of the flange into container engaging lugs and flattening intermediate portions of the flange against the inner face of the skirt.

2. The method of manufacturing metallic caps having concealed lugs with double-thickness edges, which comprises forming a blank having a top and a cylindrical skirt with a raw edge, bending a portion of the skirt adjacent the raw edge inwardly throughout its periphery to form an inwardly extending substantially planar flange with the curvature between the flange and the skirt being uniform throughout its xtent, engaging the raw edge of the flange and by a spinning action doubling the free edge of the flange upon itself and substantially in contact with the body of the flange, and thereafter forming spaced portions of the flange into container engaging lugs and flattening intermediate portions of the flange against the inner face of the skirt.

JOHN J. WILLIAMS 

